Is there anyway to make a packet client-sided? Like, how does the change Class Name work? I want to have my own client-sided stuff if anyone can teach me? Thanks.

I don't really understand what you mean...
And not everything is done by packets, there are variables and functions you have to make use of when creating a trainer.
E.g. this is the class name changer:

I don't really understand what you mean...
And not everything is done by packets, there are variables and functions you have to make use of when creating a trainer.
E.g. this is the class name changer:

Yes, that's exactly what I mean. But there's already a bunch of class changers.. How do you get the codes, and how do you put them into a trainer?
And maybe a rep changer? would that work

Oh, you mean how you actually find the variables etc in the first place?
I don't think a rep changers possible.
I use mac, so I have never done this, but people with windows use WPE Pro I believe to find them
Another way to find packets, is to just run the swf in flash professional and look for packets in the output tab. At least, that's what I have to do all the time because I'm on mac.
Another possible way, is to use Dark Mystic. There is a var scanner on it I'm not sure how effective it is, but you could try it out!

If your looking for packets, run AQWorlds through some sort of packet scanner (WPE Pro, Wireshark, Smartsniff etc) and whenever you do an action for example summoning the necro pet it'll give you a packet.

If your looking for variables, download AQWorlds shockwave file and open it up in some sort of shockwave decompiler (Sothink SWF Decompiler) and scan for variables that you want. It's recommended you have a basic knowledge of ActionScript 3 before attempting such things otherwise you'll be confused. Luckily our sweet bby Zero has uploaded a tutorials that is easy to follow.